1. Field of the Invention
The present invention relates to orthopedic appliances that help physically impaired individuals to stand and to walk. More specifically, the present invention facilitates standing and or ambulation and rehabilitation in patients otherwise unable to stand and to walk due to disability, injury, or disease.
2. Description of the Related Art
Many people are sufficiently physically impaired that they are unable to use their legs or have very limited or unbalanced use of their legs, and are thus conventionally restricted to self-powered mobility in the form of a wheelchair or stiff leg braces used with crutches or a walking frame which nearly surrounds the user. The problems and limitations faced by individuals relegated to wheelchairs are well known, and range from wheelchair related problems (e.g., building and facility access) to patient health related problems (e.g., osteoporosis and pressure sores). In response, a number of orthopedic appliances and devices have been developed to help these patients become more independent and ambulate without relying on a wheelchair.
One common device, well known in the art, is the hip-knee-ankle-foot orthosis, more commonly known as an HKAFO. HKAFOs comprise a body jacket or strap that includes a pelvic attachment connected, on each side, to a hip joint commonly having only one degree of freedom and a horizontal rotation axis. The hip joints have respective arms that are rigidly coupled, in their lower region, to the top of respective braces supporting the patient""s thigh, leg, and foot. HKAFOs are commonly custom-designed and constructed by orthotists, using commercially-available locking joint and brace components, to accommodate each individual patient""s size and physical needs. The hip joints and knee joints are unlocked when the patient using a HKAFO is seated. Using some form of assistance, the patient can then stand, lock the knee joints and hip joints, and then ambulate using a walker or crutches, employing either a swing-through or swivel gait.
Although still in common use, there are a number of problems with HKAFOs. The swing-through gait and swivel gait are both unnatural, and require a huge expenditure of energy. Even young and strong patients using a HKAFO tire quickly, and the high metabolic cost of using a HKAFO renders it impractical as a primary means of ambulation for many patients. Because the hips must remain locked to support the torso when the patient is upright, patients with some degree of hip flexor strength and mobility are prohibited from exercising and using their hip flexors to achieve a more natural gait.
The reciprocating gait orthosis (xe2x80x9cRGOxe2x80x9d) was developed to address these concerns. RGOs are similar to HKAFOs, in that they typically comprise a body jacket that includes a pelvic attachment connected, on each side, to a hip joint. Like the HKAFO, the hip joints in the RGO have respective arms that are rigidly coupled, in their lower region, to the top of respective braces supporting the patient""s thigh, leg, and foot. However, unlike the HKAFO, the hip joints in typical RGOs generally connect to one another across the body of the patient by sheathed control cables, a pivoting member, or the like, to transmit the mutual relative angular movements of the limbs. The mechanism connecting the hip joints in a RGO enables a patient to walk in a reciprocating gait, where the flexion of one leg is matched by the extension of the other leg. Therapists may find that RGOs are most appropriate for patients that have sufficient hip flexor mobility and strength to initiate a reciprocating gait, but even patients with no hip flexor power have successfully used RGOs. Some patients have found that the RGO offers easier negotiation of rough terrain, and most find the reciprocating gait to require a much lower expenditure of energy.
Nonetheless, current RGOs have limitations that can be problematic in some circumstances. Due to their more complex construction, current RGOs can be as much as 50% heavier than comparably-sized HKAFOs, and are consequently much more difficult for smaller patients and children to don. This extra weight and bulk makes the RGO more cumbersome and less comfortable than the HKAFO. One reason that some patients prefer the RGO over the HKAFO is the RGO""s capability to enable a reciprocating gait, which requires a lower energy expenditure per unit of distance than the swing-through or swivel gait requires. However, this advantage is mitigated somewhat by the extra weight of the RGO.
RGOs are ordinarily much more expensive than HKAFOs, which is again problematic for children who require more frequent orthosis replacements as they outgrow their old devices. Although reciprocating mechanisms are commercially available, many orthotists who are comfortable designing and constructing HKAFOs for their patients are not comfortable constructing an RGO. Instead, orthotists may construct the knee-ankle-foot portion and assemble it with a torso-hip portion obtained from an RGO specialist.
Finally, some newly-injured patients who may initially require the level of support provided by traditional RGOs find that the forced reciprocating motion actually impedes rehabilitation as the patient recovers and regains strength and movement. Currently, therapists may switch these patients to progressively less-restrictive orthoses during the course of therapy, but this is expensive and hinders progress because the patient must learn to operate a new and unfamiliar apparatus. Permanently disabled individuals who are not in rehabilitation or recovery may prefer a device that enables a freer range of movement than traditional RGOs, even if using such a device requires additional support such as a walker, cane, or crutches because it does not force a reciprocating gait.
Due to these limitations, ordinarily a paraplegic patient""s therapy is started using a HKAFO, rather than a RGO. If the patient does well with the HKAFO, the therapist may switch the patient to an RGO, depending upon the patient""s motivation, familial support, financial support, and a number of other factors. Many patients that have used either an HKAFO or an RGO (or both) as a primary source for ambulation eventually abandon them in favor of a wheelchair, probably due to the limitations of both devices as described above. A need thus exists for an orthotic device that combines the advantages of prior art HKAFOs and RGOs, but eliminates the current problems inherent in each device. The present invention is such an orthotic device.
The present invention is a lightweight, simple, inexpensive orthosis that provides the support found in prior HKAFOs and RGOs, but enables a freer range of independent motion than current HKAFOs and RGOs. The present invention is therefore particularly suitable for children and smaller patients, and patients in rehabilitation that are recovering some degree of motion and strength. The present invention enables independent leg movement, and is thus highly useful for patients who do not need or want the forced scissors-type motion found in traditional RGOs.
The present invention is simpler in design, structure and operation than traditional RGOs, but provides patients with the capability of ambulation using a reciprocating, rather than a swing-through or swivel gait. The advantage offered by this combination of features is twofold: ambulation with a lower metabolic cost using a reciprocating gait, using a device as lightweight and comfortable as the HKAFO. The present invention allows, rather than forces, a reciprocating gait because the present invention allows the patient independent leg movement. Moreover, therapy using present invention is more economical than the traditional RGO-assisted or HKAFO followed by RGO-assisted therapy, for several reasons. First, the device itself provides the same function as a RGO, but is less expensive and can be fabricated by any experienced orthotist. Moreover, because the present invention also functions as a HKAFO, the therapist can start the patient""s therapy with all joints locked, as though the patient were using a traditional HKAFO. Then, when the patient is ready to attempt a reciprocating gait, the waist joints can be unlocked to provide independent leg movement, without requiring a new device. Finally, the present invention adjusts to allow a recovering patient a greater degree of movement as his recovery progresses, thus eliminating or reducing the need for the recovering patient to switch to different orthoses to facilitate rehabilitation.
These and other features and advantages of the present invention will be apparent from the following detailed description and the accompanying drawings.
The present invention is a method and apparatus that facilitates standing and or ambulation by a human user. The present invention includes a posterior torso support unit securely positionable around the posterior torso and extending mid way down gluteus maximus of the user, at least one waist joint coupled to the posterior torso support unit such that the waist joint is approximately adjacent to the user""s natural waist, and at least one hip member that couples the waist joint and posterior torso support unit to a conventional leg support assembly at the hip joint. The leg support assembly is adapted to couple to the user""s leg or to replace the human user""s missing leg to provide the user stable support when the user is in an upright position. The top of the hip member couples to the waist joint, and the bottom of the hip member couples to the hip joint. The hip member is properly sized to place the hip joint approximately adjacent the user""s natural hip joint.
The waist joint of the present invention can be a commercially available free motion hip joint with 180 degree stop, such as the free motion hip joint, Model No. 1025, commercially available from Becker Orthopedic. Alternatively, the waist joint may be a joint capable of being locked and unlocked by the user. Depending upon the needs of the user, the present invention may comprise a unilateral orthotic or prosthetic device that provides the user with support on only one side, in which case the present invention would include one waist joint, one hip joint, one hip member, and one leg support assembly. Alternatively, the present invention may comprise a bilateral orthotic or prosthetic device that provides support on both sides of the user""s body. In the latter embodiment, the present invention could include right and left waist joints, right and left hip members, and right and left leg support assemblies, however, one practicing the present invention could include only one Owaist joint in a bilateral embodiment, if appropriate for a specific user.